A conventional fetal monitor and a central monitoring system composed of a plurality of the conventional fetal monitors both adopt wired probes, and each conventional fetal monitor comprises two fetal heart probes and a uterine contraction pressure probe. The connection cable of each wired probe is very long to avoid loss, but for one-to-one monitoring, one monitor is placed near each pregnant woman, the probes of the monitor are tied to the abdomen of the pregnant woman, and the three cables of the three probes are easy to twist together. Moreover, the pregnant woman cannot move freely, and the probes are required to be removed before the pregnant woman leaves the monitor, and need to be retied to the pregnant woman after the pregnant woman comes back, which is very inconvenient for use. Under the condition, each bed needs one fetal monitor in the prior art, and a plurality of fetal monitors may be arranged in one ward. Such deployment of the fetal monitors results in large number of fetal monitors, large area occupied by the fetal monitors, large electricity consumption of the fetal monitors, and difficulty of managing the data of the fetal monitors. In order to solve the problems occurred on the conventional medical wireless fetal monitoring probe, a multi-bed fetal monitor is adopted. The main principle of the multi-bed fetal monitor is that four or more groups of probes (each group of the probes comprises two fetal heart probes and one uterine contraction probe) are hung on one monitor body, a plurality of windows are displayed on one large-screen display, and each window corresponds to one pregnant woman, so that only one fetal monitor is arranged in a ward; moreover, the probes are wireless fetal monitoring probes, so that the system is concise, the occupied area is small, and the power consumption is smaller than the total power consumption of the fetal monitors arranged in one ward in the prior art. A doctor or nurse can observe the conditions of all pregnant women in one ward via the large-screen display, so that the work efficiency is improved; or, each bed can be equipped with one fetal monitor, and the fetal monitor is equipped with one group of probes (the group of the probes comprises two fetal heart probes and one uterine contraction probe), so that the cable consumption in one ward adopting the one-bed one-fetal monitor mode is reduced, and pregnant women in the ward can move freely after the probes are tied to the pregnant women. But the clinical use of wireless fetal monitoring probes in a hospital has several problems in the prior art. For example, as the wireless fetal monitoring probes are not “tied” to the fetal monitors via cables and the size of each probe is very small, the probes are easily lost and difficult to find. Moreover, as a pregnant woman can move freely after wireless fetal monitoring probes are tied to the pregnant woman, the position of the pregnant woman cannot be located fast when the doctor or nurse wants to find the pregnant woman. For example, when the doctor or nurse finds out the fetal heart rate of the pregnant woman is relatively low and the corresponding fetal monitor gives an alarm, and the doctor or nurse cannot examine the pregnant woman immediately while the pregnant woman is not in the ward. When the pregnant woman wearing the wireless fetal monitoring probes goes out of the range of a wireless pregnant network of the obstetrics and gynecology department in the hospital (e.g., taking a rest at a small garden of the hospital) without informing the doctor or nurse, the fetal heart data of the pregnant woman cannot be fed back promptly. Therefore, it cannot be known whether a probe gives an alarm or not. The doctor or nurse cannot find the pregnant woman easily, and the monitoring data and alarming events in the losing period cannot be known even the doctor or nurse finds the pregnant woman later.